Organic high polymers are readily made flame resistible by addition of an organic flame retardant and incombustible active inorganic powder. This method has been widely adopted in early stage for flame retarding organic high polymer substances (cf. U.S. Pat. Nos. 4,127,559; 4,132,748, etc).
As well known, it is supposed that an organic high polymer is decomposed by radical reactions at a high temperature on burning to low molecular weight combustible gases which serve as fuels for ignition and combustion of the high polymer, and at a higher temperature thereby, the generation of the decomposition gases is increased through chain reaction to continue the combustion.
The function of the flame retardant is extremely complicated, and its complete clarification is not yet attained. Supposedly, the organic flame retardant exerts an action to prevent the said chain reaction of combusting organic high polymers and an action to decrease the oxygen concentration in the atmosphere. Some of incombustible active inorganic powders act as an auxiliary for flame-resistivity, but they generally contribute to lowering the concentration of the combustible organic high polymer and, consequently, to reduce thereby the amount of the combustible gases to be generated by decomposition of the organic high polymer.
Even in the presence of such agents having the above mentioned activities, however, the decomposition rate of organic high polymers at a high temperature on burning and the generation of flammable gas can not be completely prevented. There is thus an limitation in the flame resistivity of organic high polymers by the use of these agents, and it is impossible by mere increase of the amount of such agents to obtain high degree flame resistivity of organic high polymers which is strongly required in recent years.
Under these circumstances, the present invention provides organic high polymer compositions being greatly improved in flame retarding property.